1,3-dihalo-2 acyloxy-2-phenyl propane and method of preparing same



United States Patent Office 3,,l02fi04 Patented Sept. 3, 1963 3,102,9041,3-DIHAL0-2 ACYLUXY-Z-PHENYL PRQT ANE AND METHQD F IPREPARTNG SAMEWillis C. Keith, Lansing, and Robert P. Zmitrovis, Park Forest, 111.,assignors to Sinclair Research, line, Wilmington, Del., a corporation ofDelaware No Drawing. Filed Nov. 20, 1961, Ser. No. 153,672 6 Claims.(Cl. 260-483) wherein R is hydrogen or a monovalent hydrocarbon radical,substituted or unsubstituted, straight, branched or cyclic, includingaromatic, of 1-20 carbon atoms. Preferably R is alkyl, advantageouslylower alkyl, for example, of 1-4 or more carbon atoms. X is halogen ofatomic number 17 to 35, preferably chlorine, and the phenyl group may besubstituted, as with one or more lower alkyl groups. An importantadvantage of the ester is its thermal stability. This is surprisingsince curnyl acetate and similar compounds are very unstable.

The ester can be made from 1,2,3-trichloro phenyl propane, which in turnmay be produced from alphamethyl styrene, for example as disclosed inour copending application Serial No. 60,117, filed October 14, 1961 nowabandoned and incorporated herein by reference. The trihalopropane isreacted with, for instance, an equimolar amount of the ammonium orequivalent, e. g., alkali metal, salts of the monocarboxylic acidcontaining the desired acyl group, that is the acid of 2-21 carbonatoms, at an elevated temperature of about 50 to 150 C. and a pressuresufficient to maintain the liquid phase. Generally, also, a liquidsolvent is employed in the reaction which may conveniently be an inerthydrocarbon but preferably is a carboxylic acid having the desired acylgroup. In a batch process the time of the reaction is generally about to30 hours but in any event is suificient to give a substantial yield ofdesired product. A large excess of the ammonium or alkali metal salt maybe used, or less than the stoichiometric amount may be employed. Nosubstantial amount of dehydrohalogenation of the trihalo propane occursin the reaction.

The following example of this invention is to be considered illustrativeonly and not limiting:

A three-neck flask equipped with a condenser, stirrer and thermowell wascharged with 73 grams of 1,2,3-trichloro-Z-phenyl propane, 65 grams ofammonium acetate and 300 grams acetic acid. The mixture was heated to 45C. and the temperature maintained for two hours. The mixture was thenallowed to reflux at 120 C. for 18 hours at about atmospheric pressure.The reaction product, 1,3-dichloro-2-acetoxy-2-phenyl propane, wasworke-d up by allowing the reaction mixture to cool to room temperatureand removing the NH Cl by filtration.

The filtrate was treated with water to form two phases, the organicphase of which was Washed with water, dried and fractionated. The 70gram product had the following characteristics:

Boiling point, O., at 2 mm. Refractive index n 25/11 Percent OFractionation was performed on a spinning band column and infraredanalysis Verified the ester group and lack of unsaturation.

it is claimed:

wherein R is a hydrocarbon radical of 1-20 carbon atoms and X is halogenof atomic number 17 to 35.

2. The compound of claim 1 where X is chlorine.

3. The compound of claim 2 where R is lower alkyl.

4. 1,3-rdlClllOl'O-2-ELCC1ZOXY-2-PhCHY1 propane.

5. A method which comprises reacting 1,2,3-trihalo- 2-phenyl propanewith the ammonium salt of an organic monocarboxylic acid of 2-21 carbonatoms at a temperature of about 50 to C. to produce wherein R is thehydrocarbon residue of the acid and X is halogen of atomic number 17 to35.

6. A method which comprises reacting 1,2,3-trichloro 2-phenyl propanewith the ammonium salt of an organic monocarboxylic acid of 2-21 carbonatoms at a temperature of about 50 to 150 C. to produce wherein R is thehydrocarbon residue of the acid.

References Cited in the file of this patent UNITED STATES PATENTS2,293,775 Soday Aug. 25, 1942 2,315,557 Soday Apr. 6, 1943 2,606,213Ladd et a1. Aug. 5, 1952 2,980,732 Girard et a1 Apr. 18, 1961 OTHERREFERENCES Chem. Abst, vol. 38, 4919' (1944).

